Autologous patellar tendon grafts are the current gold standard for replacement of irreparable anterior cruciate ligaments. Allogeneic tissue grafts are the only accepted alternative to autologous grafts and they are in extremely short supply. We propose development of non-immunogenic bovine fascia lata as a graft material for anterior cruciate replacement. The grafts will be rendered non-immunogenic by in vitro processing. The resulting collagen tissue matrix will be non-cytotoxic, biomechanically sound, and will act as a scaffold for recipient fibroblast repopulation. The proposed approaches to tissue processing will avoid use of materials which may have been responsible for effusions in the knees of human recipients of bovine xenografts. In Phase I of this project we will optimize methods for removal of cells and soluble proteins from bovine fascia lata and determine immunogenicity by subcutaneous implantation in rabbits. If the rabbit implants exhibit minimal inflammatory and immunologic cell infiltration, we will prepare a Phase II SBIR application in which bovine fascia lata is assessed as an anterior cruciate ligament replacement in a canine model. Surgical procedures and instruments for implantation and fixation of fascia lata grafts are already available because they have previously been developed for implantation of allogeneic fascia lata. PROPOSED COMMERCIAL APPLICATION: The size of the world-wide ligament market was estimated at 122,050 transplants in 1987. This study focuses on development of an immunologically modified xenograft for anterior cruciate replacement. Success in this project would permit development of bovine fascia lata grafts for other surgical applications.